Hi All,  Zephyr skin is I believe sheep intestine and can be a fine
pouch material but is not without problems.  Many years ago I recall
Dave Saul telling me that insects of some type when he was living in
Texas ate holes in zephyr skin pouches in his piano.

In the mid 1970 I wanted to get the best repetition possible on a
Welte-Mignon I was restoring for a friend.  I decided to use zephyr
skin in the primary valves since the pouches were quite small and the
pouch leather available was not as thin as I would have liked.

I was raised by a first generation American mother of German parents,
trained from age 9 as a hardwood floor man by an exacting father that
learned his trade scraping floors with a Stanley floor scraper by
hand and arm power before electric sanding machines were available and
finally educated as a Mechanical Engineer with three years of post
graduate study including steady and unsteady state fluid mechanics and
compressible fluid flow.

I know I did an excellent job but due to the fact that at least one
of the zephyr skin pouches was composed of two layers of material (do
not ask me how often this happens), after a period of two or so weeks
of perfect operation the air pressure from that one pouch found it's
way through the first of its layers and traveled between the two
layers over to and under the adjacent pouch causing a cipher.

Now, I could have just repaired those pouches but knowing the older
Murphy's Laws I decided to redo all pouches with leather.  Among the
old Murphy's Laws are (1) if something can go wrong, it will; (2) if
something goes wrong it will go wrong at the worst possible time, etc.

Allen Ford